I would've preferred that the flashback cut off at the demon lord we don't need an in depth look at how he was betrayed unless it's like right before he torture/kills another one of the traitors.
Man seriously, those bad placed Flashbacks break the whole pace of the manga. I'm out of this one. It should had been done when he met Minaris, both of theirs.
Thanks been waiting for this for so long. Really don't get what motivation they have to backstab the hero of it was fear of his power they could of reverse summoned hok and problem solved maybe they wanted the demons kings mana stone.